Symptoms:

No Reverse
Reverse slip
Low Reverse boost
Delayed engagement
Soft shifts
Poor shift quality
Low line rise
Erratic line pressure
Burnt clutches
Poor fuel economy

Cause:

OE boost sleeve deterioration allows pressure loss that leads to driveability concerns.

Correction:

Recover hydraulic control and renew shift performance by installing Sonnax drop-in boost valve kit.

5R55S, 5R55W

Boost Valve Kit
Part No. 56947J-74K

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Ford vehicles equipped with 5R55W and 5R55S transmissions frequently exhibit problems such as poor line rise, erratic line pressure, delayed engagement, no Reverse, poor shift quality and burnt clutches. These troubles can often be traced to wear in the OE boost sleeve, which allows pressure escape that causes driveability concerns. Installing Sonnax boost valve kit 56947J-74K eliminates pressure loss and revives line rise and shift quality in all ranges.

Sleeve manufactured from highly wear-resistant aluminum
Hardcoat anodized aluminum valves combat premature wear
Drop-in Zip Valve^™ parts install quickly and easily

Learn More About Zip Valve™ Drop-In Repairs

Contents

Sleeve
Inner Boost Valve
Outer Boost Valve

Valve Body Layout

Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.